JP2003321687A - Method for producing clathrate hydrate of natural gas and apparatus for production - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently produce a clathrate hydrate of natural gas with a small- sized apparatus therefor. <P>SOLUTION: The apparatus for producing the clathrate hydrate of the natural gas comprises a production vessel 2, a pair of tube sheets 7 and 8 separated to the upper and the lower sides and arranged in the production vessel 2 so as to divide the interior of the production vessel 2 into an upper space, a lower space and a body space arranged between both the spaces, a plurality of cooling tubes 9 arranged in the upper and the lower sides of the body space of the production vessel 2 so as to stride over the pair of the tube sheets 7 and 8 and having both ends opened to the upper space and the lower space, respectively, a refrigerant feeding line 13 for feeding the refrigerant to the body space of the production vessel 2, a natural gas feeding line 10 for feeding the natural gas to the upper space of the production vessel 2, a water feeding line 11 for feeding water to the upper space of the production vessel 2 and a discharge pipe 12 for discharging a mixture containing the clathrate of the natural gas produced by reacting the natural gas with the water. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a natural gas clathrate hydrate manufacturing method and apparatus for hydrating natural gas to produce a natural gas hydrate, and particularly efficiently clathrating natural gas. TECHNICAL FIELD The present invention relates to a method and an apparatus for producing a natural gas clathrate hydrate capable of producing a hydrate.

[0002]

2. Description of the Related Art Generally, various methods have been proposed as a method for processing natural gas for storing and transporting natural gas containing hydrocarbons such as methane as a main component. Methods have been proposed for hydrating natural gas under high temperature and temperature to form clathrate hydrate of natural gas.

The clathrate hydrate of natural gas is a clathrate compound in which a molecule such as methane is included and clathrated in a three-dimensional cage clathrate lattice formed by a plurality of water molecules. Two
At 0 ° C. and atmospheric pressure (about 0.1 MPa), the inclusion compound containing the same mass of natural gas has a volume of about 100 to 180 times that of natural gas in a gaseous state. Since it has a small volume and does not require cryogenic temperature to stabilize the compound, it is considered as a new processing form for storage and transportation.

Conventionally, the clathrate hydrate of natural gas is produced by attaching a refrigerant jacket to a high-pressure container, cooling the whole body, and injecting natural gas at a predetermined pressure into the container to produce natural gas and water. Was reacted to produce a hydrate of this natural gas. More recently, a method has been proposed in which cooled natural gas is supplied and sprayed with cooled water in a container kept at a constant pressure to generate a hydrate of natural gas at the contact surface between this low-temperature water and natural gas. Proposed.

[0005]

The phenomenon related to generation in any of these methods is as follows. (1) Dissolve natural gas in cold water. (2) Part of this hydrate is formed there. (3) The predetermined low temperature condition necessary for the formation of this hydrate is not satisfied due to the temperature rise due to the heat of formation, and the formation stops. (4) The supply water cannot be cooled below the freezing point of water alone, and the reaction proceeds only at a temperature below the formation equilibrium temperature, so the usable temperature range is narrow and a large amount of water is cooled and circulated. Only partly formed as the desired hydrate. (5) The production also stops when the two raw materials, natural gas and water, are separated by the production of this hydrate. Due to the above situation and the constraints resulting from this phenomenon, the conventional method for producing inclusion hydrates of natural gas requires large equipment and a large temperature difference / cooling energy due to indirect cooling for a certain amount of production. I needed it. By the way, there is a problem that the heat generated by the hydrate of natural gas is removed away from the production site, and an extra temperature difference is required for its transportation, resulting in a decrease in efficiency and an increase in the size of the device. was there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a natural gas clathrated water capable of efficiently producing a large amount of clathrate hydrate with a small apparatus. It is intended to provide a method and an apparatus for producing a Japanese product.

[0007]

In order to achieve the above object, the present invention proposes the following means. The invention according to claim 1 cools one surface with a cooling medium,
A water film is formed in a state where the other surface is in contact with water, and natural gas is supplied so that the natural gas comes into contact with the water film to react the natural gas with the water to produce a natural gas clathrate hydrate. It is characterized by According to the method for producing a clathrate hydrate of natural gas according to the present invention, a water film is formed when water is supplied to the other surface whose one surface is cooled by the cooling medium. When natural gas is supplied in contact with the formed water film, the natural gas reacts with water to produce a hydrate. The heat generated by the formation of the hydrate is promptly removed by the refrigerant in contact with the outer surface of the cooling pipe with which the water film is in contact, and the temperature rise due to the heat of formation is suppressed so that it does not become a factor limiting the amount of formation. Therefore, a clathrate hydrate of natural gas can be produced in large quantities and in a chain.

According to a second aspect of the present invention, the outer surface is cooled to a predetermined temperature by a cooling medium and a plurality of vertically arranged cooling pipes are allowed to flow down in contact with water to form a water film. A natural gas clathrate hydrate is produced by supplying natural gas to a water film so that the natural gas reacts with the water. According to the method for producing a natural gas clathrate hydrate according to the present invention, when natural gas comes into contact with the water film formed on the inner surface of the cooling pipe after being cooled to a predetermined temperature, the natural gas reacts with water to react with the natural gas. Gas hydrate is produced.
Since the area of the water film is large due to the plurality of cooling pipes arranged, the clathrate hydrate of natural gas can be efficiently produced. In addition, when water falls in the cooling pipe due to its own weight while forming a water film, a stirring action of water itself occurs, which promotes molecular movement and heat transfer at the interface between water and natural gas.
This promotes the formation of clathrate hydrate.

According to a third aspect of the invention, in the method for producing a natural gas clathrate hydrate according to the second aspect, the water is caused to flow down while rotating in the cooling pipe.
According to the method for producing a natural gas clathrate hydrate according to the present invention, since water flows down while rotating in the cooling pipe, the natural gas comes into contact with the water film and the natural gas reacts with the water to react with the natural gas. When the clathrate hydrate of water is formed on the surface of the water film, the clathrate hydrate of the natural gas is crushed by the water disturbed by the rotation, so that a new contact surface between the natural gas and water is formed. To do.
Since the contact surface between natural gas and water is always formed, the clathrate hydrate of natural gas can be continuously produced.

According to a fourth aspect of the present invention, there is provided a vertical cylindrical production tank, a space serving as a pipe inlet for natural gas and water at an upper end in the vertical cylindrical production tank, and the raw material and the production at a lower end. And a pair of tube plates vertically separated from each other in the production tank so as to partition into the outlet collection space of the hydrate and the body space arranged between the two spaces, and the body space of the production tank. A plurality of cooling pipes that are arranged so as to extend vertically so as to straddle the pair of tube plates, and have both ends opened to the upper space and the lower space, respectively, and a coolant is supplied to the body space of the production tank. A refrigerant supply line, a natural gas supply line that supplies natural gas to the upper space of the production tank, a water supply line that supplies water to the upper space of the production tank, and the natural gas from the lower space of the production tank. Natural produced by reacting with water Characterized in that it comprises a discharge pipe for discharging a mixture comprising a scan clathrate hydrate. According to the natural gas clathrate hydrate production apparatus of the present invention, when natural gas and water are supplied from the upper space of the production tank, the water forms a water film while being cooled through the cooling pipe. As it flows down, the natural gas reacts by contacting the formed water film to form an inclusion hydrate of natural gas. The formed clathrate hydrate of natural gas is discharged together with unreacted natural gas and unreacted water as a mixture to the outside of the production tank by a discharge pipe located in the lower space of the production tank. At this time, since a plurality of cooling pipes are arranged, the water film has a large area and the contact area with natural gas is large, so that a hydrate of natural gas can be efficiently produced.

According to a fifth aspect of the present invention, in the apparatus for producing a clathrate hydrate of natural gas according to the fourth aspect, each of the cooling pipes has the upper portion so that the openings of the cooling pipes have the same height. It is characterized in that it is arranged so as to project upward from the tube sheet. According to the apparatus for producing natural gas clathrate hydrate according to the present invention, when the water is supplied to the upper space of the production tank by the water supply line, the openings of the respective cooling pipes are formed to have the same height. Therefore, the supplied water flows down in each cooling pipe at the same time when it reaches the height of the opening of each cooling pipe.
This water has a sufficient flow cross-sectional area below the height of the opening of each cooling pipe and up to the tube plate, so the water surface gradient from the water supply hole to the upper end opening of each cooling pipe is sufficient. Since it can be made small, almost the same amount of water film is formed in each of the multiple cooling pipes, so the contact area between the water film and natural gas becomes larger, and the hydrate of natural gas is efficiently formed. Can be manufactured.

According to a sixth aspect of the invention, in the apparatus for producing a natural gas clathrate hydrate according to the fourth or fifth aspect, a guide hole is provided at an upper end portion of the cooling pipe to impart rotation to water flowing into the cooling pipe. Is provided. According to the apparatus for producing natural gas clathrate hydrate according to the present invention, the water supplied to the upper space of the production tank is rotated by the guide hole and flows down while rotating in the cooling pipe. When natural gas comes into contact and natural gas reacts with water to form a hydrate of natural gas, the hydrate of natural gas is crushed by water disturbed by rotation and removed from the water film surface. Therefore, a contact surface between natural gas and water is newly formed. Since the contact surface between natural gas and water is always formed, the clathrate hydrate of natural gas can be continuously produced.

According to a seventh aspect of the present invention, in the apparatus for producing a natural gas clathrate hydrate according to the fourth or fifth aspect, the inner wall of the cooling pipe has a spiral shape that imparts rotation to water flowing into the cooling pipe. It is characterized in that the uneven portions of are formed. According to the apparatus for producing natural gas clathrate hydrate according to the present invention, the water supplied to the upper space of the production tank is rotated by the spiral irregularities and the water flow is disturbed in the cooling pipe. As it flows down, when natural gas comes into contact with the water film and the natural gas reacts with water to form a hydrate of natural gas, the hydrate of natural gas was disturbed by the rotation and the irregularities. Since it is crushed by water and removed from the surface of the water film,
A new contact surface between natural gas and water is formed. Since the contact surface between natural gas and water is always formed, it is possible to continuously produce a hydrate of natural gas.

The invention according to claim 8 is the apparatus for producing a clathrate hydrate of natural gas according to any one of claims 4 to 7, wherein the mixture discharged from the discharge pipe is provided downstream of the production tank. It is characterized by comprising a product separation tank for separating the. According to the apparatus for producing natural gas clathrate hydrate of the present invention, the mixture of natural gas clathrate hydrate containing unreacted natural gas and unreacted water is unreacted in the product separation tank. Almost all of the natural gas and most of the unreacted water are separated, and the clathrate hydrate is dispersed in water at a high concentration to form a sludge state, and the clathrate hydrate of natural gas is discharged. This makes it possible to reduce the load of the subsequent dehydration step of removing water from the clathrate hydrate of natural gas.

According to a ninth aspect of the present invention, in the apparatus for producing a clathrate hydrate of natural gas according to the eighth aspect, the liquid separated in the product separation tank is added to the product separation tank. An unreacted water recycle line for supplying to the upper part and an unreacted natural gas recycle line for supplying the unreacted natural gas separated in the product separation tank to the upper part of the production tank are provided. . According to the apparatus for producing clathrate hydrate of natural gas according to the present invention, unreacted natural gas and unreacted water separated in the product separation tank are supplied to the production tank. Is used to form clathrate hydrate of natural gas. Therefore, it is possible to suppress the waste of natural gas, and it is possible to produce a clathrate hydrate of natural gas at a reduced cost by not requiring a large amount of new water.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the invention. In FIG. 1, a natural gas clathrate hydrate production apparatus 1 includes a production tank 2 in which natural gas and water are supplied to produce a natural gas hydrate, and a clathrate hydrate of the produced natural gas. A product separation tank 3 for separating a substance from unreacted natural gas and unreacted water is a main constituent element.

The production tank 2 includes a production tank upper lid 4 which covers the upper space 2a in the production tank 2 from above, a production tank lower lid 5 which covers the lower space 2b in the production tank 2 from below, and the inside of the production tank 2. Body space 2 located between the upper space 2a and the lower space 2b
It is composed of a production tank body 6 which covers c from the side, and between the upper space 2a and the body space 2c in the production tank 2, and between the lower space 2b and the body space 2c in the production tank 2. The production tank upper tube sheet 7 and the production tank lower tube sheet 8 are provided as a pair and are vertically separated from each other. In the body space 2c of the production tank 2, a pair of the production tank upper tube sheet 7 and the production tank lower tube sheet 8 are formed.
A plurality of vertically extending cooling pipes 9 are arranged so as to straddle the space, and both ends of the opening of the cooling pipe 9 are opened toward the upper space 2a and the lower space 2b in the production tank 2, respectively. .

The production tank 2 has an upper space 2a in the production tank 2.
Generated from natural gas supply line 10 for supplying natural gas to untreated water, unreacted water recycling line (water supply line) 11 for supplying water to upper space 2a in production tank 2, and lower space 2b in production tank 2 as well. A discharge pipe 12 is provided for discharging the hydrate of natural gas produced by the reaction in the tank 2 to the outside of the production tank 2 as a mixture together with unreacted natural gas and unreacted water. 6, a cooling medium supply line 13 for supplying a cooling medium to the body space 2c and a body space 2c.
And a cooling medium return line 14 for drawing the cooling medium from the cooling medium.

The product separation tank 3 has a discharge pipe 12 through which the mixture discharged in the production tank 2 flows, and a product separation tank 3
The unreacted natural gas recycle line 15 for supplying the unreacted natural gas separated in the production tank 2 and the unreacted water separated in the product separation tank 3 for the production tank 2 A reaction water recycling line 11 and a reaction product extraction line 17 for discharging the natural gas hydrate separated in the product separation tank 3 are provided. An unreacted water circulation pump 18 for circulating water is attached in the middle of the unreacted water recycling line 11. The unreacted natural gas recycling line 15 is connected to the natural gas supply line 10, and the discharge pipe 12 is connected to a water supply pipe 19.

As shown in FIG. 2, the cooling pipes 9 have upper opening ends A of the respective cooling pipes 9 projecting upward from the production tank upper tube sheet 7,
Each upper opening end A is formed to have the same height, and in the upper part of the cooling pipe 9, a gap (guide hole) opened in a tangential direction that gives rotation to water when water flows into the inside.
A guide hole ring 20 having 20a is provided. (See Figure 3)

Next, the operation of the natural gas clathrate hydrate producing apparatus 1 having the above-mentioned structure will be described. First, the cooling medium is circulated in the body space 2c by the cooling medium supply line 13 and the cooling medium return line 14 to cool each cooling pipe 9 to a predetermined temperature, for example, 5 ° C. Next, since there is no unreacted water in the first time, water is sent to the product separation tank 3 through the water supply pipe 19 through the discharge pipe 12, and the unreacted water circulation pump 18 is used through the unreacted water recycling line 11 to generate water. Water is supplied to the upper space 2a in the unit 2. The supplied water is stored on the upper tube plate 7 of the production tank, and when the water surface reaches the upper opening end A of each cooling pipe 9, the upper opening end A of each cooling pipe 9 is stored.
Over and over to flow down along the inner wall of the cooling pipe 9. At this time, since the upper opening end A of each cooling pipe 9 is formed at the same height, approximately the same amount of water flows into each cooling pipe 9 at the same time.
Further, since the cooling pipe 9 is provided with the guide hole ring 20 having the gap 20a opened in the tangential direction, the water flowing in each cooling pipe 9 is in a state of being rotated by the guide hole ring 20. Run down.

In this state, the natural gas supply line 1
When 0, natural gas is supplied to the upper space 2a in the production tank 2 at a predetermined pressure, for example, 2 MPa. The supplied natural gas reacts by contacting with a water film formed along the inner wall of the cooling pipe 9 to generate a hydrate of natural gas. At this time, a separator film made of a hydrate is formed on the contact surface between the natural gas and water to hinder the contact between the natural gas and water, and the heat of formation hinders the formation of the hydrate. Since the water flowing in the pipe 9 is rotated by the guide hole ring 20 and the water flow is turbulent, the clathrate hydrate of the generated natural gas falls in the agitated state, so that the water film is formed. The hydrate thin film formed on the surface is crushed and the direct contact between the liquid water film and the natural gas is maintained. Also, since the thin water film is being stirred and cooled from a close range by the refrigerant in contact with the outside of the cooling pipe wall with which it is in contact, the heat of formation due to the hydrate formation reaction is immediately removed. The temperature inside the cooling pipe 9 is kept substantially uniform, and the hydrate is continuously and rapidly produced.

The produced natural gas hydrate is discharged to the outside of the production tank 2 as a mixture containing unreacted natural gas and unreacted water. The exhaled mixture is discharged from the discharge pipe 1.
It is supplied to the product separation tank 3 via 2 and almost all the unreacted natural gas and most unreacted water are separated in the product separation tank 3, and the inclusion hydrate of natural gas is partially unreacted. It is discharged as a sludge of water and clathrate hydrate with the reaction water. The separated unreacted water is supplied to the production tank 2 through the unreacted water recycling line 11, and the separated unreacted natural gas is
Generation tank 2 through unreacted natural gas recycling line 15
Is supplied to. The separated sludge of the clathrate hydrate of natural gas is extracted through the reaction product extracting line 17.

After the unreacted water is generated, the unreacted water is supplied to the production tank 2 through the unreacted water recycling line 11,
Water is replenished through the water supply pipe 19 as needed, and a hydrate of natural gas is produced in the same manner.

According to the above construction, when the natural gas and the water are reacted in the cooling pipe 9 to generate the clathrate hydrate of the natural gas, the guide hole ring 20 flows down the cooling pipe 9. Since the rotating water is given the rotation to disturb the water flow, the contact between the natural gas and the water is promoted, and as a result, the clathrate hydrate can be continuously produced. Further, since the heat of reaction is removed by the smaller temperature gradient due to the disturbance of the water flow, the temperature inside the cooling pipe 9 is kept substantially uniform. As a result, the hydrate is continuously and quickly produced, and more hydrate can be produced at the same time.

Further, since unreacted natural gas and unreacted water are supplied to the production tank 2 by the unreacted natural gas recycle line 15 and the unreacted water recycle line 11, respectively, waste of natural gas is suppressed. In addition, it is possible to produce a hydrate of natural gas with a small-sized apparatus while suppressing the cost thereof without requiring a large amount of new water.

Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram showing a cooling pipe 9 according to the second embodiment of the present invention. In FIG. 4, the cooling pipe 9
A spiral groove 21 (uneven portion) is formed along the inner wall of the. Other parts are the same as those in the first embodiment.

In the natural gas clathrate hydrate production apparatus 1 having the above-described structure, the water flowing in each cooling pipe 9 flows down while being rotated by the spiral groove 21. In this state, if natural gas is supplied at a predetermined pressure,
As with the first embodiment, a clathrate hydrate of natural gas is produced. At this time, the water flowing down in the cooling pipe 9 is spiral groove 21.
Since the water is turbulent due to the rotation by the water, the clathrate hydrate of the generated natural gas falls in the cooling pipe 9 in a more agitated state, and the generation of the hydrate is more continuous. Will be done promptly.

According to the above structure, when the natural gas and water are reacted in the cooling pipe 9 to generate a hydrate of natural gas, the water flowing down in the cooling pipe 9 by the spiral groove 21 is Since the water flow is disturbed by the rotation, the contact between the natural gas and water is further promoted, and as a result, the hydrate can be produced more continuously. Further, since the temperature inside the cooling pipe 9 is kept more uniform, the hydrate is generated more continuously and rapidly, and more hydrate can be simultaneously produced. Although the spiral groove 21 is formed on the inner wall of the cooling pipe 9 in FIG. 4, a spiral protrusion may be used instead of the spiral groove 21.

In the above embodiment, the reactor for reacting natural gas and water was constructed as the cooling pipe 9.
The reactor for reacting natural gas and water is not limited to this.

[0031]

As described above, according to the invention of claim 1, when natural gas is supplied so as to be in contact with the formed water film, the natural gas and water react with each other to form a hydrate. It is possible to produce a clathrate hydrate of natural gas.

According to the second or fourth aspect of the invention, since the plurality of cooling pipes are arranged, the area of the water film is large, and therefore the contact area with the natural gas is large, so that the size is efficiently reduced. The equipment can produce hydrates of natural gas.

Further, according to the invention of claim 3, 6 or 7, when the natural gas and water are reacted in the cooling pipe to generate a hydrate of natural gas, the inside of the cooling pipe is guided by the guide hole. Since the flowing water is given rotation to disturb the water flow, the contact between the natural gas and water is promoted, and as a result, a hydrate of natural gas can be continuously produced.

Further, according to the invention of claim 5, the supplied water flows down through each cooling pipe at the same time when the height of the opening of each cooling pipe is reached. By uniformly forming the water film, the inside of the entire cooling pipe is effectively used as the contact area between the water film and the natural gas, and the hydrate of natural gas can be efficiently produced.

According to the invention of claim 8, the mixture of natural gas clathrate hydrate containing unreacted natural gas and unreacted water is separated in the product separation tank to produce natural gas. Since the hydrate is extracted as high-concentration water / slurry, the load of the subsequent steps can be reduced.

Further, according to the invention of claim 9, the unreacted natural gas and the unreacted water are effectively utilized to form the clathrate hydrate of the natural gas, thus wasting natural gas. In addition to being able to suppress the amount of water, it is possible to produce a hydrate of natural gas at a reduced cost by not requiring a large amount of new water.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an apparatus for producing a natural gas clathrate hydrate according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing a production tank of the natural gas clathrate hydrate production apparatus according to the first embodiment of the present invention.

FIG. 3 is a schematic view showing an upper portion of a cooling pipe of the apparatus for producing natural gas clathrate hydrate according to the first embodiment of the present invention.

FIG. 4 is a half sectional view showing a cooling pipe of a natural gas clathrate hydrate production apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

1 Natural gas clathrate hydrate production equipment 2 production tank 7 Production tank upper tube sheet 8 Production tank lower tube plate 9 Cooling pipe 10 Natural gas supply line 11 Water supply line 12 Discharge pipe 13 Refrigerant supply line 20a Guide hole (gap) 21 Concavo-convex part (spiral groove) A opening (upper opening end)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07C 7/20 C07C 9/04 9/04 F28C 3/08 F24J 1/00 F28F 1/40 D F28C 3 / 08 C10L 3/00 A F28F 1/40 F24J 1/02 (72) Inventor Kimihiro Sawa 3-2-16 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center F-term (reference) 4G075 AA02 BA10 BD03 BD08 BD13 BD26 CA03 CA51 DA02 DA12 EA01 EA05 EB01 EC07 EE12 FA01 4H006 AA02 AD33 AD40 BC10 BE60

Claims (9)

[Claims] 1. A water film is formed in a state where one surface is cooled by a cooling medium and water is in contact with the other surface, and natural gas and water are supplied so that natural gas contacts the water film. A method for producing a natural gas clathrate hydrate, which comprises reacting with a natural gas to produce a natural gas clathrate hydrate. 2. An outer surface is cooled to a predetermined temperature by a cooling medium and a plurality of vertically arranged cooling pipes are allowed to flow down in a state where water is in contact with the inner surfaces of the cooling tubes to form a water film. A natural gas clathrate hydrate is manufactured by reacting the natural gas with water to supply the natural gas clathrate hydrate. 3. The method for producing a natural gas clathrate hydrate according to claim 2, wherein the water is caused to flow down while rotating in the cooling pipe. . 4. A pair of a production tank and a pair of upper and lower spaces that are vertically spaced apart from each other so as to partition the interior of the production tank into an upper space, a lower space, and a body space disposed between these spaces. A tube plate, a plurality of cooling tubes arranged in the body space of the production tank so as to extend vertically so as to straddle the pair of tube plates, and both ends of which are respectively opened to the upper space and the lower space; A refrigerant supply line for supplying a refrigerant to the body space of the production tank, a natural gas supply line for supplying natural gas to the upper space of the production tank, and a water supply line for supplying water to the upper space of the production tank, A natural gas clathrate hydrate, comprising: a discharge pipe for discharging a mixture containing a natural gas clathrate hydrate produced by a reaction between the natural gas and the water from a lower space of the production tank. Equipment for manufacturing things. 5. The apparatus for producing a natural gas clathrate hydrate according to claim 4, wherein the cooling pipes project upward from the upper tube sheet so that the openings of the cooling pipes have the same height. An apparatus for producing a natural gas clathrate hydrate, characterized in that 6. The apparatus for producing a natural gas clathrate hydrate according to claim 4 or 5, wherein a guide hole for rotating water flowing into the cooling pipe is provided at an upper end portion of the cooling pipe. An apparatus for producing a natural gas clathrate hydrate characterized by: 7. The apparatus for producing a natural gas clathrate hydrate according to claim 4 or 5, wherein the inner wall of the cooling pipe is provided with a spiral uneven portion that imparts rotation to water flowing into the cooling pipe. An apparatus for producing a natural gas clathrate hydrate characterized in that: 8. The apparatus for producing a clathrate hydrate of natural gas according to claim 4, wherein product separation for separating the mixture discharged from the discharge pipe is provided downstream of the production tank. An apparatus for producing a natural gas clathrate hydrate, comprising a tank. 9. The apparatus for producing a natural gas clathrate hydrate according to claim 8, wherein unreacted water is supplied to the product separation tank, and the liquid separated in the product separation tank is supplied to the production tank. A natural gas clathrate hydrate characterized in that a recycle line and an unreacted natural gas recycle line for supplying the unreacted natural gas separated in the product separation tank to the reactor are provided. Manufacturing equipment.